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A296993
Numbers k such that k^3 divides tau(k), where tau(k) = A000594(k) is Ramanujan's tau function.
3
1, 2, 4, 6, 8, 16, 24, 32, 64, 96, 128, 256, 288, 384, 512, 1024, 1536, 2048, 4096, 6144, 8192, 16384, 18432, 24576, 32768, 65536, 98304, 131072, 172032, 262144, 276480, 393216, 524288, 1048576, 1179648, 1572864, 1935360, 2097152, 2621440, 3538944, 4194304
OFFSET
1,2
COMMENTS
2^k is a term for k >= 0.
LINKS
Eric Weisstein's World of Mathematics, Tau Function.
PROG
(Python)
from itertools import count, islice
from sympy import divisor_sigma
def A296993_gen(startvalue=1): # generator of terms >= startvalue
return filter(lambda n: not -24*((m:=n+1>>1)**2*(0 if n&1 else (m*(35*m - 52*n) + 18*n**2)*divisor_sigma(m)**2)+sum((i*(i*(i*(70*i - 140*n) + 90*n**2)))*divisor_sigma(i)*divisor_sigma(n-i) for i in range(1, m))) % n**3, count(max(startvalue, 1)))
A296993_list = list(islice(A296993_gen(), 10)) # Chai Wah Wu, Nov 08 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Dec 22 2017
STATUS
approved